Writer-director Harmony Korine’s new film, Spring Breakers, is the graphically violent tale of four hard-partying, lawbreaking college girls gone wild, a movie stuffed to the gills with booze, drugs, nudity, crime, guns, and general mayhem. The real surprise? It stars two of the most famous graduates of the squeaky-clean, family-friendly Disney Channel machine: Selena Gomez, 20, and Vanessa Hudgens, 24. On a warm February afternoon, the 40-year-old cinematic bomb-thrower behind films like Kids and Gummo and his two stars met up at a Los Angeles hotel to explain one of the year’s most improbable cinematic matchups.

A hypersexual, hyperviolent R-rated movie about college students robbing people on spring break doesn’t sound like something that would star Vanessa Hudgens and Selena Gomez. Where did the idea to cast them come from?

HARMONY KORINE You always start off with the dream of: If you could have anybody, who would it be? And without even auditioning them or knowing what their abilities were — just on a conceptual level — I was like, ”These girls are representative of a pop mythology I find really interesting.” And I just thought they looked perfect for the part. So those were the first names I threw out.

Vanessa and Selena, how familiar were you with Harmony’s movies? You were literally kids when Kids, which he wrote, came out in 1995 and stirred up huge controversy.

Vanessa Hudgens Both of our parents were big fans of Harmony’s, actually. They were excited just to see his name on the script and were like, ”Go for it with everything you’ve got!” I’ve always gravitated towards movies that shake me up, and after seeing Kids, I was definitely in shock. But that’s what I live for. So right off the bat I was really excited, because it was completely different.

Selena Gomez My mom is my manager, so she was the first one that read this script, and she freaked out because she’s a huge Harmony fan. So we watched all of his movies. I don’t really picture myself when I watch, like, Trash Humpers or Mister Lonely. [Laughs] There was obviously a part of me that didn’t picture myself in something like that. But there was something cool about that, and there was something that really spoke to me in the character of Faith.

Korine I’m older than Selena’s mom. It’s so trippy. [Laughs]

What was your first meeting like?

Korine My casting person said, ”Selena and her mom are coming to Nashville, and she’s going to audition at your house.” I was excited because I wanted her in the movie, but I didn’t know anything at all about her personal life. I knew she had done a lot of work with Disney and all these family-oriented things, so I assumed that maybe she was really religious or something. And I have a lot of crazy artwork in my house, so I was like, ”Oh s—, I don’t want to freak her out right off the bat, have her open the door and there’s all these things that are overwhelming.” So I just started flipping photographs over — all these gnarly things.

Like what kinds of things?

Korine Like [Nobuyoshi] Araki, this Japanese photographer who ties women up — but they’re beautiful. [Pauses] I’m not going to describe s— to you because then it’s going to sound super-perverted: ”There’s a picture where she takes a cucumber and shoves it up her —” [Laughs] But then they walked in the door, and within a couple of minutes it was great. I was kind of blown away. It just shows you can never predict anything.

While making this movie, you were down in St. Petersburg, Florida, among real spring breakers.

Hudgens: That part was actually fun. Just being around that energy — it gives you so much. We got to feed off of it and it was just a blast.

Gomez There was one moment when Harmony wanted me to dance with all these frat guys — I got a little nervous about that. I remember I said, ”Can I have [costar] Rachel [Korine] in this scene with me?” But once I was in there, they were really nice — and a little intoxicated. Actually, a lot intoxicated.

I assume you guys were not actually doing bong hits and snorting coke.

Korine They were snorting kilos of vitamins.

Gomez I didn’t do that part, but it was really funny because it’s vitamin B-12, which gives you energy. So it was the funniest thing: They were like, “Oh, it’s so gross, but now I’m super-energetic!”

James Franco plays a gun-toting hip-hop thug named Alien who brings your characters into his world. What was it like working with him?

Hudgens I have no idea who James is. I know who Alien is very well. But James never left his character, which was so amazing. Aside from that, he was quiet — he’d be reading a book in the corner. But he was absolutely brilliant. He’s a genius.

It’s obviously tricky to transition from teen stardom in High School Musical or Wizards of Waverly Place to an adult acting career. Was part of the appeal of doing this movie that you could just burn down those past images all at once?

Gomez As far as image, for me it’s exhausting to have to make a decision based on that, because that’s not why I do what I do. My TV show, my music, my clothing line — all of those things I get to do for other people. But at the end of the day, I love what I do — for me. I was really fortunate to be a part of the [Disney Channel], but it was also very controlled. It’s a machine, and they definitely know what they’re doing. I’m completely grateful for it. Disney has been an incredible part of my life. But it was really refreshing for me to take a chance. And look, I don’t even know if there’s a right answer to make sure the transition is smooth. It’s scary. But we’ll see. We can only hope for the best.

Hudgens I think it was just a way for us to grow, honestly. I mean, we do this because we love acting. This was an opportunity to really push our boundaries.

Have you watched how other actresses have tried to make that transition?

Hudgens Everyone has their own journey. I’m creating my own story, and I want it to be unique. The key thing for me has just been doing what I’m passionate about, not doing things I think are mediocre because someone else tells me to. I’m only doing things that I’m infatuated with, and I’m saying no more than I say yes. I think that’s what’s going to allow people to look at me in a different way and make that transition. Like Selena said, I don’t know if it’s going to work. But I’m enjoying it and I’m proud of what I’m doing.

Gomez It’s been fun getting the reactions we’ve gotten, whether it’s ”What are you thinking?” or ”Oh my goodness, that’s amazing!” Because [in the past] I’ve had to make sure that I represented something I’ve done in a very politically correct way. So it’s been refreshing to hear sometimes that it’s shocking.